Grinding machine



July 8, 1924.

. 1,500,401 E; LAUER-SCHMALTZ GRINDING MACHINE Filed June 23 1920 6Sheets-Sheet l E. LAUER-SCHMALTZ GRINDING MACHINE [110d Jun0'23 1920 6Sheets-Sheet 2 E. LAUER-SCHMALTZ GRINDING MACHINE Filed Jun. 23 1920 6Sheets-S 5 July 8, I924. 1,500,401

E. LAUER-SCHMALTZ GRINDING MACHINE Filed Jun023 1920 6 Sheets-Sheet 4 6Sheets-Sheet 5 GRINDING MACHINE *Filod Jun. 23 1920 1,500,401 E.LAUER-SCHMALTZ July 8, 1924;

GRINDING MACHINE Filed Jul-M23 1920 6 Sheets-Sheet 6 as a drivingpulley;

Patented July 8, 1924.

UNITED STATES EUGEN LAUER-SCHMALTZ, OF O'FFENBACH-ON-THE-MAIN, GERMANY.

GRINDING MACHINE.

Application filed June 23, 1920. Serial No. 391,241.

To all whom it may concern:

'Be it known that ;I, EUGEN LAUER- SCHMALTZ, a citizen of Germany, and aresident of Ofl'enbach-on-the-Main, Germany, have invented certain newand useful Improvements in Grinding Machines,- for which I have filedapplications for patents in Germany Sch. No. 50,970, January 15th, 1917,and Sch. 54,619, February 26th, 1919, and of which the following is aspecification.

My invention relates to grinding machines, and comprises the mounting ofthe grinding wheel or disc directly on the external rotor element of anelectric motor, and the combination of parts substantially ashereinafter described and claimed.

' In the accompanying drawings, in which like parts are similarlydesignated,

Figure '1 is an elevation of a grinding machine having a motor withbell-shaped armature;

Fig. 2 is an elevation of a modified form of grinding machine;

Fig. 3 shows the external rotor casing, with grinding disc removed andoperating Fig. 4 is a three-phase short-circuited motor having adisc-shaped cage armature;

Fig. 5 is a cross-section of the same;

Fig. 6 is a three-phase short-circuited motor with a differentarrangement of discshaped cage armature;

Fig. 7 is a cross-section of the same;

Fig. 8 is a cross-section of a three-phase short-circuited motor havinga ventilated bell-shaped armature;

Fig. 9 is a cross-section'of a continuous or alternating current motorand its commutator or collector;

Fig. 10 is a view partly in longitudinal section of a specialconstruction of the'motor according to Figs. 8 and '9, in which thegrinding wheel is fastened to the armature rotor i Fig. 11 is a likeview of a three-phase current segment motor with bell-shaped contactring-armature;

Fig. 12 shows a motor in the rotating casing of crank shaft grindingmachines and its current supply;

Fig. 13 illustrates a portable motor'that can be attached a)different-kinds otmachine tools.

In all the' constructions shown the rotor or armature of the motorcarries the grinding tool, and is on the outside-of the stator or fieldstructure, and the grinding [tool'has sufficient space to operate evenwhen of disc shape. r

In my machines, motors for continuous current with disc-shaped armaturerequire a displacement of the field winding outside the grinding wheellimit, and the poles must be arranged out of the symmetrical radius sothat the grinding tool has enough space to attack the object to beground. In order not to change the efiiciency of the motor the ends ofthe pole-shoes are kept as far as possible in symmetrical arrangement,and the pole shoe space is made as narrow as possible.

In special constructions, for instance in grinding apparatus forunusually thick journals, it is also permissible either to omit one poleor to make it smaller, and the efficiency of the motor is accordinglydecreased.

The disc-shaped and bell-shaped armature arrangement permits the use ofany current, but it is necessary, as with large types for three phasecurrent with Contact ring-armature, to arrange the parts so that thecommutator or current collector, or contact rings, are capped dust-tighton the inside of the rotor to prevent short-circuiting by the grindingdust.

With a bell-shaped armature the grinding tool may beeither fixed oradjustable on the armature. The whole construction is then held by abolt or a flange-shape elongation enclosing the stator and carrying thegrinding disc 4. This armature is provided with peripheral ribs vforming a pulley between which a belt to may run to drive an auxiliaryspindle-u carrying a grinding disc. Fig. 3 is a similar view omittingthe disc 4 and 'showingithe armature without grooves, but

acting as a driving pulley.

The simplest form of motor is the threephase motor Figs. 4 and 5, withsquirrelcage armature (short-circuited armature),

the windings of which are arranged at the inside surface ofthe grindingring on the disc flange that carries the grindingring, so that theoutside grinding wheel surface and one side surface is free forgrinding. In this case the rotor 1 and the grinding ring 4 are carriedby the hub flange 2, or the flange is made in one piece with a hub asshown. The grinding ring 4 is held in place by the removable ring flange3. The rotor is mounted on ball-bearing 5, Fig. 5, and is securedagainst side movement by thrust ball bearings 6. The ball bearings 5 areheld in the stator casing 7, which is made plate-shaped in order toreduce the width of the construction. The stator casing holds thering-shaped laminated iron core 8 through the grooves of which any kindof current is passed. The space for this winding is seen at 10.

In order to get a construction that is more compact in diameter, thethree-phase motor may be built as shown in Figs. 6 and 7. In this casethe rotor 1 is made as a disc arn1ature and assembled with the disc 2that carries' the grinding ring. The remainder of the construction isthe same as in Figs. 4 and 5, except that the ring-shaped iron core 8,which is made of strap iron, has its active face on the side.

A three-phase motor with bell-shaped armature, shown in Fig. 8 has thebolt like stator holder 20 preferably hollow and fastened with the nut21. The stator iron 8 is attached to the bolt 20 by a wedge or feather22, andcarries the three-phase field winding 10 inthe grooves or slots9. The bell-shaped rotor casing 2 is mounted on the bolt byball-bearings 5, secured to the bolt by ring nuts 23, and covers all theelectrical parts, and has in its inside the short-circuited armaturelwhich is fixed thereto by a wedge or feather 24. The armature iron islaminated and the bell 2 carries on the outside the grinding disc-ring26 with the grinding wheel 4, thereon and the securing nut 3. The ringwith the wheel thereon is movable in axial direction, as indicated bythe dotted by feather or cotter 25.

line positions, but secured against turning The bell 27 in smaller typesofmachines, may be made with ribs or ventilating wings 28, Fig. 8 andcan be built into the ring space. A good cooling ;of the electricalsystem is obtained if the air stream passes through the interior of bolt2O in the direction of the arrow, so that,

when grinding no water spray can penetrate into theuns de of the motoragainst this air -stream issuing at 28. Packing rings for V dust "andwater-spray are built in front of the bearing at 19;

T The "continuous or alternating current motor, Fig; 9 is in all partsexactly as the above-descr'ibed motor, and the same refer- 'enc'echaracters are used for the corresponding parts. The difference betweenthe contionary pole-holder casing 20, which struction of Figs. 8 and 9is, that in the latter on the armature iron 1 is placed a winding 16,that is in connection with'the commutator or collector 17, and that abrushholder 29, with brushes 18 is pivoted in a 5M fork-shaped bolt 30,which is solidly con nected with the central bolt 20. The brushholder 29is urged against the commutator or collector by the spring 31.

Fig. 10 shows a special construction of the motor the parts of which arelimited to narrow dimensions. Here the grinding wheel 4, which is heldby the flange 26 and the nut 3, is tightly held at one side of thearmature, and the ventilating arrangement 28 is L beveled off a littleon one side so that it is easier to work between collars.

In the before described constructions ballbearings are used for thearmature. It is also possible to use the motor with journalbearings ofany kind of construction.

In the following described vertical arrangement of a grinder of largecapacity, Fig. 11, the armature casing 2 has a hollow bearing-journal32,. which runs in a split bushing 34. The bearing-journal 32 is securedagainst vertical movement by a double-thrust ball-bearing 35. Theadjustment of the bearing construction is effected by screws 36. Themotor is otherwise of the same type as the one before mentioned, and theparts are correspondingly numbered. In place of the holding bolt we havea sta- 1s flanged-connected to the machine head 37. The contact rings 38which are in conductive connection with the armature winding 16, are onthe upper outside of the armature 2, not on the inside, and may becapped so that splash-water will not reach the electrical parts. Throughthe central bore 39 of the bearing-journal 32 the water is-suppliedcentrally to the grinding head and to the segments 4, which may beattached in any manner desired.

The assembling of a motor with a-discshaped armature in a crank-shaftgrinding machine is shown for example in Fig. 12. In the latter figurewe see that no gear and belt drives are necessary for operating thegrinding wheel, but only the contact-rings 43, which are electricallyconnected with the motor, and are capped dust-tight in the encirclinggrinding wheel holder.

In Fig. 12, 0 designates the stationary housing that contains the usualrotating ring 6, carrying a guard 49. Mounted on a pin 47 in the guard49 is the holder or support 48 for the stator casing 7. On the hubflange 2 is the grinding disc 4, and on the support are the fieldmagnets 10. The work is indicated by 11. The pivoted support 48 carries,a gear segment 50 which meshes with a pinion 60. The pinion 60 iscarried by a gear wheel 61 and the gear no Wheel 61 meshes with a gearwheel on a spindle operated by a hand wheel 51.

By operating the hand wheel 51 in one direction the grinding disc 4 ismoved toward the work, and by operating the hand wheel in the oppositedirection the grinding disc 4 is moved from the work.

The current is supplied to the contact 44 mounted in the housing 0;current passes to the ring 43 and is taken from said ring 43 by theconductor 46.

The ring I) in rotating carries the guard 49 along with it.

A portable grinding machine for use on different machine tools such aslathes,

planers, rolling-mills and other such machines, is shown in Fig. 13. Themotor holder 45 is adapted to the kind of machine to be used.

In this figure, 7 designates the stator casing; 2 the hub flange; 4 thegrinding disc; 11 the work and 10 the field windings. The stator casinghas a radial shank 45 by which it is secured or mounted in any desiredmachine tool. The machine tool here shown, in part, is a lathe having across slide 54. Mounted on the cross slide 54 is a slide 52 at rightangles to the cross slide. The shank is held in a tool clamp 53 on theslide 52. I claim: l. The combination with a field member and asupporting pin therein: of a bellshaped armature enclosing said fieldmemher, a grinding tool directly mounted on the exterior cylindricalportion of said armature, and means on said armature for the receptionof a driving belt.

2. The combination with a field member having a hollow supporting pin ofa bellshaped armature enclosing said field member, a tool directlymounted on the exterior cylindrical portion of said armature, and meansto permit the adjustment of the tool across the face of said cylindricalportion of the armature.

3. The combination with a bell shaped armature, of a stator enclosed inthe armature, a central hollow supporting pin passing through the fieldmember, bearings between the field member and armature at each endthereof, a tool, and means to permit the adjustment of the tool acrossthe outer cylindrical face of said bell shaped ara mature.

EUGEN LAUER-SCHMALTZ.

